Outcomes/Effectiveness Research

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Unrecognized intracranial injury can produce permanent brain damage, severe disability, and even death. As such, many doctors require blunt head injury patients to undergo computerized tomography (CT) imaging of the head. However, of the nearly one million blunt trauma patients who undergo head CT imaging each year in the United States, only 6 percent prove to have significant intracranial injuries. A new study identifies clinical characteristics that can reliably identify blunt head injury patients at low risk for intracranial injury, who do not require CT imaging.

William R. Mower, M.D., Ph.D., and colleagues, supported by the Agency for Healthcare Research and Quality (HS09699), analyzed data on all blunt trauma patients who had head CT scans ordered by the managing physician at 21 study centers. Clinicians collected limited demographic information, documented the presence or absence of certain clinical variables, assessed each patient's Glasgow Coma Scale (GCS) score, and the presence of "neurologic deficit" (combined elements of GCS with abnormal gait, cranial nerve abnormality, or motor deficit).

A total of 13,738 patients (median age of 40) were enrolled, and 917 were diagnosed with clinically important intracranial injuries (including 330 with minor head injuries). The researchers identified eight characteristics that were independently and highly associated with intracranial injuries: evidence of significant skull fracture, scalp hematoma (swelling), neurologic deficit, altered level of alertness, abnormal behavior, coagulopathy (blood
clotting disorder), persistent vomiting, and age 65 years or older. These 8 factors correctly identified 901 of the 917 patients with clinically important intracranial injuries. The researchers conclude that patients without these characteristics are at low risk for intracranial injury.

More details are in "Developing a decision instrument to guide computed tomographic imaging of blunt head injury patients," by Dr. Mower, Jerome R. Hoffman, M.A., M.D., Mel Herbert, M.B.B.S., and others, in the October 2005 Journal of Trauma, Injury, Infection, and Critical Care 59, pp. 954-959.